myset = set('hello')
print('myset: %s' % myset)
print('len myset: %s' % len(myset))
for ch in myset:
    print(ch)

aset = set('abc')
bset = set('cde')
print('aset & bset: %s' % (aset & bset))
print('aset.intersection(bset): %s' % aset.intersection(bset))
print('aset | bset: %s' % (aset | bset))
print('aset.union(bset): %s' % aset.union(bset))
aset.add('new')
print('aset: %s' % aset)
aset.update(['aaa', 'bbb'])
print('aset: %s' % aset)
aset.remove('bbb')
print('aset: %s' % aset)
cset = set('abcde')
dset = set('bcd')
print('cset.issuperset(dset): %s' % cset.issuperset(dset))
print('cset.issubset(dset): %s' % cset.issubset(dset))